58 



L. W. SOWL 



that they could keep the fox away from the 

 birds on Agattu. This is evidence of an Aleut 

 recognition of serious competition. Could cor- 

 morants, particularly red-faced cormorants, 

 have been preferred sources of fiber? Were 

 Aleuts forced to rely more heavily on cor- 

 morant skins as puffin and guillemot numbers 

 were reduced by rats and fox and sea otters 

 by men? 



Whatever the cause and effect, the status of 

 red-faced cormorants now appears to be 

 better in the Gulf of Alaska than for at least 

 the last 100 years. 



Glaucous-winged Gull (Larus glaucescens) 



The glaucous-winged gull is apparently one 

 of the more successful seabirds breeding in 

 the Gulf of Alaska. While it is outnumbered 

 (both locally and in total abundance) by the 

 black-legged kittiwake, it is generally the 

 most commonly seen and most uniformly dis- 

 tributed gull in the Gulf of Alaska. Murie 

 (1959) called it the common breeding gull 

 about the Alaska Peninsula. Cahalane (1943, 

 1944) considered it to be numerous to abun- 

 dant around Kodiak and in the Shelikoff 

 Strait area. Gabrielson (1944) reported that it 

 could be seen in small numbers everywhere. 

 Most recently, Isleib and Kessel (1973) re- 

 ported it to be an abundant resident in the 

 north Gulf Coast area. My own experience 

 would confirm these observations. 



This gull appears to use a wider variety of 

 nesting sites than some others (Gabrielson 

 and Lincoln 1959). Except where man's activi- 

 ties have created new food sources, there ap- 

 pears to be a close link between the location of 

 glaucous-winged gull colonies and those of 

 murres, kittiwakes, and cormorants. Swartz 

 (1966) found that during the breeding season 

 glaucous-winged gulls at Cape Thompson de- 

 rived almost all of their food from murre eggs 

 and chicks. I have noted small numbers of 

 these gulls nesting, usually on turf near the 

 tops of cliffs, in most colonies of favored prey 

 species. 



The glaucous-winged gull is the principal 

 scavenger throughout much of coastal south- 

 central Alaska. This has sometimes resulted 

 in the development of large concentrations 

 near canneries and, more recently, near 

 dumps. 



Two glaucous-winged gull concentrations 

 stand out in the northern Gulf of Alaska. One 

 of these is on Egg Island at the western end of 

 the Copper River Delta. Patten (1976) esti- 

 mated that this colony contained 10,000- 

 12,000 gulls in 1975. At times it appears to 

 spread onto nearby Hinchinbrook Island. 

 M. E. Isleib (personal communication) has es- 

 timated its size as high as 25,000 gulls. The 

 other large concentration is on the Susitna 

 Flats across Cook Inlet from Anchorage. This 

 colony, or colony cluster, may be larger than 

 the one at Egg Island. There are no other 

 known colonies even approaching these in 

 size. Most colonies range between a few pairs 

 and 2,000-3,000. 



Glaucous-winged gulls do not appear to 

 have had any great changes in population 

 that can be detected from the literature. 

 There have almost certainly been local fluc- 

 tuations in the number of breeding birds as 

 food supplies, such as canneries and dumps, 

 have appeared or disappeared in an area. 

 Long-term changes in salmon runs have un- 

 doubtedly had an impact as well. One other 

 change, the reduced level of egging, has un- 

 doubtedly had an effect also. Along the 

 Alaska Peninsula and in the Shumagin Is- 

 lands, cannery workers of Filipino heritage 

 and fishermen who have a strong Aleut heri- 

 tage still harvest gull eggs for food. However, 

 this activity is much reduced from what it 

 must have been. 



Herring Gull (Larus argentatus) 



The herring gull is a resident of Upper Cook 

 Inlet and is found up and down the coast from 

 Prince William Sound to the Alaska Penin- 

 sula. Not too much was learned about it dur- 

 ing the recent FWS reconnaissance. William- 

 son and Peyton (1963) reported the inter- 

 breeding of herring gulls and glaucous-winged 

 gulls in this area. This interbreeding has re- 

 sulted in a situation in which assignment of 

 these gulls to one group or another in the field 

 can be rather arbitrary. The result has most 

 often been that field observers tend to lump 

 them with glaucous-winged gulls unless their 

 herring gull characteristics are obvious. 

 Specimens collected by Williamson and Pey- 

 ton (1963) indicate that herring gulls have the 

 edge in numbers in Upper Cook Inlet. 



